18.5.10.13 The ndbinfo nodes Table

This table contains information on the status of data nodes. For
each data node that is running in the cluster, a corresponding
row in this table provides the node's node ID, status, and
uptime. For nodes that are starting, it also shows the current
start phase.

The following table provides information about the columns in
the nodes table. For each column, the table
shows the name, data type, and a brief description. Additional
information can be found in the notes following the table.

Column Name

Type

Description

node_id

integer

The data node's unique node ID in the cluster.

uptime

integer

Time since the node was last started, in seconds.

status

string

Current status of the data node; see text for possible values.

start_phase

integer

If the data node is starting, the current start phase.

config_generation

integer

The version of the cluster configuration file in use on this data node.

The uptime column shows the time in seconds
that this node has been running since it was last started or
restarted. This is a BIGINT
value. This figure includes the time actually needed to start
the node; in other words, this counter starts running the moment
that ndbd or ndbmtd is
first invoked; thus, even for a node that has not yet finished
starting, uptime may show a non-zero value.

The status column shows the node's
current status. This is one of: NOTHING,
CMVMI, STARTING,
STARTED, SINGLEUSER,
STOPPING_1, STOPPING_2,
STOPPING_3, or STOPPING_4.
When the status is STARTING, you can see the
current start phase in the start_phase column
(see later in this section). SINGLEUSER is
displayed in the status column for all data
nodes when the cluster is in single user mode (see
Section 18.5.8, “NDB Cluster Single User Mode”). Seeing one of
the STOPPING states does not necessarily mean
that the node is shutting down but can mean rather that it is
entering a new state; for example, if you put the cluster in
single user mode, you can sometimes see data nodes report their
state briefly as STOPPING_2 before the status
changes to SINGLEUSER.

The config_generation column shows which
version of the cluster configuration is in effect on each data
node. This can be useful when performing a rolling restart of
the cluster in order to make changes in configuration
parameters. For example, from the output of the following
SELECT statement, you can see
that node 3 is not yet using the latest version of the cluster
configuration (6) although nodes 1, 2, and 4
are doing so:

Therefore, for the case just shown, you should restart node 3 to
complete the rolling restart of the cluster.

Nodes that are stopped are not accounted for in this table.
Suppose that you have an NDB Cluster with 4 data nodes (node IDs
1, 2, 3 and 4), and all nodes are running normally, then this
table contains 4 rows, 1 for each data node: